Gear box



FIG. 1 is a top perspective view of a gear box showing my new design;

FIG. 2 is a right side elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a front elevational view thereof; and,

FIG. 5 is a rear elevational view thereof.

The ornamental design for a gear box, as shown.